﻿// Copyright 2008 Chris Varley (http://www.contractdriven.net/)
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

using System;

namespace ContractDriven.CommonAssertions
{
    /// <summary>
    /// Used by the Throws and DoesNotThrow methods.
    /// </summary>
    public delegate void ThrowsDelegate();

    public abstract class BaseThrowsAssertion : IAssertion 
    {
        public ThrowsDelegate TestCode {get;protected set;}
        public Type ExpectedType { get; protected set; }

        protected BaseThrowsAssertion(ThrowsDelegate testCode)
        {
            Contract.Require(Assert.IsNotNull(testCode));

            TestCode = testCode;
        }

        #region IAssertion Members

        public string FailureDescription { get; protected set; }

        public abstract bool Eval();


        #endregion

        internal Exception Throws()
        {
            Exception exception = Record.Exception(TestCode);

            if (exception == null)
                return null;

            if (ExpectedType == null)
                return exception;

            if (!ExpectedType.Equals(exception.GetType()))
                return null;

            return exception;
        }
    
    }

    

    
}
